Black spots on arms may be caused by coffee spots, seborrheic keratosis, flat warts and other diseases, which can be treated with medication and physical therapy. 1. Coffee spots: If the black spots on the arm are caused by coffee spots, most patients do not need treatment. If it affects the appearance, patients can follow the doctor’s instructions for laser treatment, through the selective photothermal effect, directly on the melanin, nevus pigmented tissue particles, which can be achieved by eliminating black spots. 2. Seborrheic keratosis: for seborrheic keratosis caused by black spots on the arm, the disease is generally based on physical therapy, you can follow the doctor’s orders to use cryotherapy, through the liquid nitrogen generated by the low temperature so that the lesion tissue necrosis, eliminating black spots. The patient can also carry out laser treatment, through the selective photothermal destruction principle to destroy the diseased tissue, eliminating the black spots. 3. flat warts: if flat warts caused by black spots on the arm, the patient can use CO2 laser, liquid nitrogen freezing and other physical therapy to destroy the lesion tissue, eliminating black spots on the arm. Patients can also follow the doctor’s instructions to use topical retinoic acid ointment and imiquimod ointment, which can promote epidermal exfoliation and indirect antiviral effects, thus improving the spots. There are many reasons that lead to black spots on the arm, and it is recommended that patients go to the hospital to clarify the cause of the disease and then standardize the treatment.